Semiconductor device and method for manufacturing the same

A semiconductor device, comprising:

• a base;
• a first silicon carbide region including at least one selected from the group consisting of nitrogen, phosphorus and arsenic, at least a part of the first silicon carbide region including fluorine;
• a second silicon carbide region including at least one selected from the group consisting of boron, aluminum and gallium, the first silicon carbide region being provided between the base and the second silicon carbide region;
• a third silicon carbide region;
• a first electrode;
• a second electrode;
• a third electrode;
• and
• an insulating portion,
• wherein
• the first silicon carbide region includes a first position in a first direction from the base to the first silicon carbide region,
• in a fluorine concentration profile along the first direction, a fluorine concentration has a first peak value at the first position,
• the third silicon carbide region includes at least one selected from the group consisting of nitrogen, phosphorus and arsenic,
• a direction from the first electrode to the second electrode is along the first direction,
• the first silicon carbide region includes a first partial region and a second partial region,
• the second silicon carbide region includes a third partial region and a fourth partial region,
• the third partial region is located between the first partial region and the third silicon carbide region in the first direction,
• a direction from the second partial region to the third electrode is along the first direction,
• the fourth partial region is located between the second partial region and the third silicon carbide region in a second direction crossing the first direction,
• the first electrode is electrically connected to the first silicon carbide region,
• the second electrode is electrically connected to the third silicon carbide region, and
• the insulating portion is provided between the second partial region and the third electrode.

A method for manufacturing a semiconductor device, the method comprising:

• preparing a structure body, the structure body including a base, a first silicon carbide region and a second silicon carbide region, the first silicon carbide region including a first impurity element, the first impurity element including at least one selected from the group consisting of nitrogen, phosphorus and arsenic, the second silicon carbide region including a second impurity element, the second impurity element including at least one selected from the group consisting of boron, aluminum and gallium, the first silicon carbide region being provided between the base and the second silicon carbide region in a first direction from the base to the first silicon carbide region;
• introducing fluorine into the first silicon carbide region;
• and
• irradiating at least part of the first silicon carbide region with at least one selected from the group consisting of hydrogen, helium and electron prior to the introducing the fluorine.